feat(mcp): Dabit.Mcp 초기 공개 (리네임 + colors 수정 + scroll 검증)

- refactor: DabitChe.Mcp → Dabit.Mcp (namespace, csproj, exe 모두)
- fix: display_message colors를 쉼표 구분 문자열로 변경 (ModelContextProtocol 1.3.0 배열 바인딩 버그 우회)
- docs: scroll 4방향(left/right/up/down) 실기 검증 완료 (DIBD600T V3.6.1)

20 도구 (읽기 4 + 콘텐츠 2 + 설정 14), stdio 전송, Windows exe.
실기 검증: scroll/fill_screen 8색/display_message 글자별색 모두 정상.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Dabit.Mcp/Tools/BrightnessPowerTools.cs

@@ -0,0 +1,59 @@
+using System.ComponentModel;
+using Dabit.Mcp.Services;
+using DibdProtocol.Protocol;
+using Microsoft.Extensions.Logging;
+using ModelContextProtocol.Server;
+
+namespace Dabit.Mcp.Tools;
+
+/// <summary>밝기·전원 설정 도구. ⚠️ 쓰기.</summary>
+[McpServerToolType]
+public sealed class BrightnessPowerTools
+{
+    private readonly LedControlService _led;
+    private readonly ILogger<BrightnessPowerTools> _log;
+
+    public BrightnessPowerTools(LedControlService led, ILogger<BrightnessPowerTools> log)
+    {
+        _led = led;
+        _log = log;
+    }
+
+    // 밝기 단계 0~4 → (표시%, HEX byte). 정본 SettingsViewModel 매핑 그대로(byte-identical).
+    private static readonly (int Pct, byte Hex)[] BrightnessMap =
+    {
+        (100, 0x64), (75, 0x48), (50, 0x32), (25, 0x19), (5, 0x05),
+    };
+
+    [McpServerTool]
+    [Description("전광판 밝기를 설정한다. ⚠️ 쓰기·설정 저장. level 0~4: 0=100%, 1=75%, 2=50%, 3=25%, 4=5%.")]
+    public async Task<string> SetBrightness(
+        [Description("밝기 단계 0~4 (0=100% 1=75% 2=50% 3=25% 4=5%)")] int level,
+        CancellationToken ct = default)
+    {
+        if (level < 0 || level > 4)
+            return "밝기 단계는 0~4여야 합니다 (0=100% 1=75% 2=50% 3=25% 4=5%).";
+        var (pct, hex) = BrightnessMap[level];
+        var resp = await _led.SendHexAsync(HexCommand.SetBrightness, new[] { hex }, ct, 5000);
+        var (ok, msg) = LedControlService.CheckWriteStatus(HexCommand.SetBrightness, resp);
+        return ok ? $"밝기 {pct}% 설정." : $"밝기 설정 실패 — {msg}";
+    }
+
+    [McpServerTool]
+    [Description("전광판 LED 전원을 켠다. ⚠️ 쓰기.")]
+    public async Task<string> LedPowerOn(CancellationToken ct = default)
+    {
+        var resp = await _led.SendHexAsync(HexCommand.LedPowerControl, new byte[] { 0x01 }, ct);
+        var (ok, msg) = LedControlService.CheckWriteStatus(HexCommand.LedPowerControl, resp);
+        return ok ? "LED 전원 켜짐." : $"전원 켜기 실패 — {msg}";
+    }
+
+    [McpServerTool]
+    [Description("전광판 LED 전원을 끈다. ⚠️ 쓰기 — 화면이 꺼진다.")]
+    public async Task<string> LedPowerOff(CancellationToken ct = default)
+    {
+        var resp = await _led.SendHexAsync(HexCommand.LedPowerControl, new byte[] { 0x00 }, ct);
+        var (ok, msg) = LedControlService.CheckWriteStatus(HexCommand.LedPowerControl, resp);
+        return ok ? "LED 전원 꺼짐." : $"전원 끄기 실패 — {msg}";
+    }
+}